This invention relates to a medical diagnostic ultrasound system and method for post-processing. In particular, a system and method for removing the effects of persistence and other post-processing is provided.
Ultrasound systems transmit acoustic waveforms and generate ultrasound data representing echo signals along a plurality of scanlines. The ultrasound data provided by receive beamformers undergoes various processes to generate an image on a display. These processes include focal gain compensation, dynamic range adjustment, various forms of filtering, display gray level mapping, and depth gain compensation.
For example, persistence processing or filtering is performed. Typically, an infinite impulse response (IIR) filter filters ultrasound data samples representing the same location at different times. This data is filtered as a function of one filter coefficient, typically labeled alpha (xcex1). The amount of persistence may be changed as a function of the filter coefficient.
Ultrasound data altered by the various ultrasound image processes discussed above is used to generate an image and may be output to other devices, such as remote viewing stations or temporary or semi-permanent image storage memory. The ultrasound data is formatted for transfer to remote viewing stations. For example, the DICOM format is used. Pursuant to this format, the processed ultrasound data is provided with information indicating the patient, time of examination and various parameters indicating the type and amount of processing used to generate the transferred ultrasound data. Some of these descriptors are standard and some are added as proprietary variants. Processors at the remote viewing station use the ultrasound data to generate an image. The patient information and processing information is also displayed with the image. However, imaging the same region of the same patient with a different amount or types of ultrasound image processing may require the patient to be scanned again, requiring an expensive and inconvenient repeat examination.
The present invention is defined by the following claims, and nothing in this section should be taken as a limitation on those claims. By way of introduction, the preferred embodiment described below includes a medical diagnostic ultrasound method and system for processing ultrasound data. Ultrasound data is generated by a receive beamformer. Ultrasound image processing is applied to the ultrasound data for presentation of an image. Various ones of the ultrasound image processing steps may be reversed. For example, persistence processing may be reversed in order to obtain ultrasound data associated with data prior to persistence processing. This recovered data may be used to generate an image or for application of a different amount of persistence. Other processes that may be reversed to recover ultrasound data include focal and depth gain compensation, dynamic range compression, intensity or color mapping, and various filtering steps, such as persistence or spatial filtering.
In one embodiment described below, the recovery of ultrasound data through the reversal of various ultrasound image processes is performed by a remote work station. The remote work station is provided with various parameters representing the type and amount of ultrasound image processing used to generate the ultrasound data. Based on this information, the remote viewing station recovers the ultrasound data. In other embodiments, the ultrasound data is processed to estimate the amount of ultrasound image processing. The estimates are then used to recover ultrasound data through reversal of the ultrasound image processing.
In one aspect, a medical diagnostic ultrasound system and method for processing ultrasound data is provided. A beamformer obtains ultrasound data. At least one of various processors or other devices ultrasound image process the ultrasound data in response to at least one ultrasound image processing parameter. A processor reverses at least some of the ultrasound image processing as a function of the ultrasound image processing parameter.
In a second aspect, a medical diagnostic ultrasound system and method for persistence processing is provided. At least two frames of persisted ultrasound data are obtained. At least two frames of reduced persistence ultrasound data are recovered from the at least two frames of persisted ultrasound data. In further aspects, the reduced persistence ultrasound data is recovered based on either a known persistence coefficient or an estimated persistence filter coefficient.
Further aspects and advantages are discussed below in conjunction with the preferred embodiments.